X-ray free electron lasers (XFELs) produce quasi-monochromatic, highly-coherent, sub-100-fsec pulses of x-rays that are a billion times brighter than any synchrotron. The LCLS XFEL in the USA first lased in 2009, and research there is fundamentally changing how x-ray diffraction, spectroscopy and imaging are used by providing the ability to probe and understand the dynamics of matter on atomic length- and time-scales. The ultra-short x-ray pulse lengths from XFELs mean that they are ideal for making detailed x-ray scattering studies of extreme states of matter that exist for only a few billionths of a second. But progress at the LCLS has been constrained by the relatively low repetition rate of the LCLS, and the quality and repetition rate of the optical lasers used to create the short-lived states. As a result, while the transformative capabilities of XFELs have been demonstrated by the applicants at the LCLS over the last 5 years, progress has been limited. The European x-ray free electron laser (EXFEL) in Hamburg commenced operations in Sept 2017, and produces high-energy x-rays at unprecedented repetition rates. Furthermore, the UK-supplied DiPOLE diode-pumped optical laser that will be installed at EXFEL in 2019 will be vastly superior to the LCLS equivalent, having 5 times the energy, 2000 times the repetition rate, and the ability to change the laser pulse shape as required in real time. To exploit the £30M capital being invested by BEIS in the EXFEL project, the £8M invested by STFC and EPSRC in DiPOLE, and the £3M pa. UK contribution to EXFEL running costs, we have brought together a team of the leading UK researchers in XFEL and high-pressure science with the aim of combining EXFEL and DiPOLE to make transformative x-ray scattering studies of high energy density solids and liquids and metastable phases. We aim to understand how the remarkably complex properties of different phases of matter emerge from the correlations of the atomic or electronic constituents, and how to control and tailor these properties so that metastable states might be recovered to ambient conditions, leading to a whole new field with a gamut of practical applications.

Since the beginning of humanity our societies have been based on commerce, i.e. we make things and we sell them to other people. Relatively simple beginnings led to the Industrial Revolution and now to the technological age. Over-generalising, the Far East are currently the masters of mass manufacture and the West are (or wish to be) the masters of advanced manufacture - the production of high-value goods, often involving a significant degree of innovation. To be able to manufacture goods in a cost-effective, environmentally-sustainable manner, quality control procedures are required. And quality control in turn requires an appropriate measurement infrastructure to be in place. It is a sub-set of this measurement infrastructure that is the subject of this fellowship. The UK government has been investing heavily in advanced manufacturing. In the academic arena, there are the sixteen EPSRC Centres of Innovative Manufacturing. To ease the pain of transferring academic research to the manufacturing sector, there are the seven High-Value Manufacturing Catapults (the Manufacturing Technology Centre being the main one of note here). For industry, there are a number of funding initiatives and tax breaks. To support this burgeoning UK advanced manufacturing infrastructure, there are a small number of academic centres for metrology - those based at Huddersfield and Bath are the main players. And, at the top of the measurement tree, there is the world-class National Physical Laboratory - a centre of excellence in metrology. But, there are still some gaps in the manufacturing metrology research jigsaw, and the aim of this fellowship is to plug those gaps. Coordinate metrology has been used for decades in the manufacturing industry as the most dominant form of process control, usually employing tactile coordinate measuring machines (CMMs). However, due to the slow speed of tactile systems and the fact that they can only take a limited amount of points, optical CMMs are starting to flourish. On the smaller scale, there are many optical surface measuring devices that tend to be used off-line in industry. When making small, high-precision, complex components, with difficult to access geometries, it is a combination of the surface measurement systems and the CMMs that is required. This requirement is one of the main aims of the fellowship - to develop a suite of fast, high-accuracy, non-contact measurement systems, which can be employed in industry. These principles will also be applied to the field of additive manufacturing - a new paradigm in manufacturing which is seeing significant government support and, in some cases, media hype. As with high-precision components, a coordinate metrology infrastructure for additive manufacturing is required, in many cases in-line to allow direct feedback to the manufacturing process. This is the second field of metrology that the fellowship will address. The outputs of the fellowship will be in the form of academic publications; new measurement instruments, along with new ways to use existing instruments; methods to allow manufacturers to verify the performance of their instruments; and the necessary pre-normative work that will lead to specification standards in the two fields (currently lacking). The academic world will benefit from the fundamental nature of elements of the research, and the industrial manufacturing world will benefit from the techniques developed and routes to standardisation. But, ultimately, it will be the UK citizens that will reap the greatest benefit in terms of new and enhanced products, and the wealth creation potential from precision and additive manufacturing.